Study links moderate belly weight to sound sleep

November 12, 2012 by Maureen Azuh

MAUREEN AZUH writes on a study that indicates that getting rid of belly fat can cure insomnia

For many people, falling asleep may seem like an impossible task. This is despite the fact that there have been reports that following healthy sleep habits can make the difference between restlessness and restful slumber.

However researchers have identified other practices and habits that can improve sleep quality. One of the most recent is weight loss. According to researchers from John Hopkins University, USA, losing weight, whether from changing diet or a combination of diet change and exercise, can improve sleep quality.

The study was funded by the National Heart, Lung, and Blood Institute, the National Centre for Advancing Translational Sciences and presented at the American Heart Association Scientific Sessions on November 6.

The researchers were led by a Professor of medicine at the university’s School of Medicine and director of clinical and research exercise physiology, Kerry Stewart, and a doctor at the Yale University School of Nursing, Soohyn Nam. They found that improvement in sleep quality was significantly associated with overall weight loss, especially belly fat.

The report says for the six-month study, the researchers enrolled 77 people who had type 2 diabetes or pre-diabetes. The participants, all of whom also were overweight or obese, were randomly assigned to one of two groups. One group went on a weight-loss diet and had supervised exercise training, while the other group only had the diet intervention. A total of 55 participants completed all phases of the study.

The participants filled out the Hopkins Sleep Survey at the beginning and end of the study to identify sleep problems, including sleep apnea, daytime fatigue, insomnia, restless sleep, excessive sleep or sleepiness and use of sedatives to aid sleep. Their body mass index and amount of abdominal fat were also measured at the start and end of the study.

The two groups – those assigned to a weight loss diet plus supervised exercise and those who only went on a diet – lost about 15 pounds, on average. They also lost about the same amount of belly fat, about 15 per cent, which was assessed by magnetic resonance imaging – MRI.

According to the researchers, although a variety of sleep problems were reported by the participants, none stood out as being the most common. So, they – researchers – analysed a composite score, which reflects overall sleep health. What they found was that both groups improved their overall sleep score by about 20 per cent with no differences between the groups.

Stewart says, “The key ingredient for improved sleep quality from our study was a reduction in overall body fat, and, in particular belly fat, which was true no matter the age or gender of the participants or whether the weight loss came from diet alone or diet plus exercise.”

He also notes that good sleep quality is important in general for good physical and mental health, as well as for a healthy cardiovascular system.

“Depending on the cause, chronic sleep disruptions increase the risk of high blood pressure, heart attack, stroke and irregular heartbeats. Obesity increases the risk of sleep problems,” he says.

In a similar study carried out in September 2012, researchers also found that adequate sleep helps weight loss. The researchers add that adequate sleep is an important part of a weight loss plan and should be added to the recommended mix of diet and exercise.

Although they also recommend calorie restriction and increased physical activity for weight loss, they posit that there is significant evidence that inadequate sleep is contributing to obesity. Lack of sleep increases the stimulus to consume more food and increases appetite-regulating hormones.

“An accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction programme to a patient with obesity. Sleep should be included as part of the lifestyle package that traditionally has focused on diet and physical activity,” the authors say.